With the development of computer technology, a computer, which includes a display portion (i.e., screen portion) and a host detachable from each other, has been developed. For example, in some models of portable computers, the display portion is composed of an embedded system and a liquid crystal display screen, while the host portion operates based on an X86 system. The detached display portion can function as a tablet computer alone or as a complete portable computer in combination with the host portion.
There are at least the following problems with the prior art. In a portable computer, and many other situations as well, some devices or units of the host portion need not always be in an active and power-consuming state. Furthermore, in some particular situations, there may be a security risk if the devices or units of the host portion are always in the active state.